Other Parts Discussed in Thread: TM4C1290NCPDT
I am using a DRV8816 EVM board to run a uni-directional solenoid using three methods.
Method 1: The solenoid is connected between the OUT1 and OUT2 pins. The solenoid works fine using this method. The plunger travels completely back and forth.
Method 2: The solenoid is connected between the OUT2 and SENSE pins. The plunger travels completely to one direction (the coil is compressed). But, when the voltage is reduced to 0V with the POT, the plunger does not move back to the initial condition. I can see that the plunger is trying to move, though.
Method 3: The solenoid is connected between the OUT2 and the ground pins, but this way I cannot measure the current flowing through the sense resistor because the ground pin bypasses the sense resistor.
My questions are:
1) Do I need to add a diode for an EMF protection across the solenoid?
2) Could you please explain why the solenoid does not work the same way as Option 1 when Option 2 is used? What is causing the strange behavior for Option 2?